HobbyKing.com New Products Flash Sale

Acme Aircraft C-170 Laser Cut Kit Review

Martin Hunter explores this great looking, great flying scale kit...that starts as an easy to build box of laser cut pieces, and ends looking fabulous in the sky, sun glinting off the chrome...

Splash

Introduction


Wingspan:36"
Wing Area:175 sq. in.
Weight:7-8 oz.
Weight as Tested:8.8 oz (see text)
Wing Loading:7.2 oz/sq. ft.
Servos:Two Micro Servos
Transmitter:Three+ Channel
Receiver:Three+ Channel Micro
Battery:2 cell 400 to 1000 lipo
Motor:Himax 2208-1260
Prop:APC 7x4 Electric
ESC:10A Brushless
Manufacturer:Acme Aircraft

Take a drive to your local municipal airport and what do you see? Typically you'll see all manners of light civilian aircraft doing touch and goes, sight-seeing, and training. Unfortunately in this regard, when it comes to R/C aircraft, typically the first light private aircraft modelled are the less popular (nowadays anyways) civilian birds like the Piper Cub. It is with this in mind that Acme Aircraft has released a unique light single in the way of their C-170 parkflyer. With a light wing loading and small size, the C-170 looked to be capable of small field operations without undue stress on the pilot. As the icing on the cake, the fact that the C-170 is a balsa kit allowed me to build something unique - a rare thing nowadays!

Kit Contents

Not shown in the above photo is a small bag of miscellaneous hardware, which includes the following:

  • 4/40 plastic screw and blind nut for wing hold-down
  • Screws for the Himax motor (not included)
  • 1" piece of 1/8" dowel for the wing mount
  • clear acetate for the windscreen and side windows
  • an abundance of CA hinge material
  • washers to add to the motor mount screws if right thrust is desired (see "Completion")

What Is Needed To Complete This Kit?

The C-170 kit came mostly complete but left a few things out in order to save costs a little and also leave some options open to the builder. In addition to the hardware and electronics listed below, I opted to add a full function lighting system as well as a thicker covering to give the plane a more "solid" look. More on that in the "Covering" section.

Hardware

Following is a list of hardware required to finish the C-170 kit. Varations to these are, of course, at the builder's discretion.

  • Main Wheels: 1.5" Dubro foam wheels work and look the best
  • Tail Wheel: Any 1/2" to 3/4" tailwheel will do
  • Pushrods: 0.032" music wire

Electronics

As with any other electric aircraft, there were countless possible combinations that would work in the C-170. However, the intention of the C-170 was to be a lazy circuit flyer, so with that in mind I stuck with the motor/battery setup as recommended by Acme Aircraft. Additionally, the firewall was already designed with the Himax 2208 in mind so fit was to be a non-issue. Larger motors in a plane like this would do little more than add weight, both in the motor itself as well as in the required battery. Following is the list of required electronics with my specific choices.

  • Motor: The design is specifically setup for a Himax 2208-1260 Outrunner though any similar motor would suffice. See the "Completion" section for my personal power charts on this motor
  • Electronic Speed Control: Any 7 to 10A ESC will do, brushed or brushless as appropriate. In this case, a Castle Creations Phoenix-10 was used
  • Servos: Two micro servos are required. A pair of GWS Pico BB servos were used for the review aircraft
  • Receiver: Any 3+ channel micro receiver will work. A Castle Creations Berg 4 was used in this case.

Assembly

Tail Feathers

Construction started, as per usual, with the tail feathers. The outlines were all laser cut and interlocking, with a perfect parts fit. Despite the fact that there were no part numbers on the individual pieces, the parts were all grouped together on the parts sheets rather than scattered around, and as such finding the specific pieces for each assembly was no challenge.

Fuselage

The fuselage construction was quite straight-forward and resulted in a dead-true fuselage. Construction techniques are what have become the norm for semi-scale parkflyers. Flat plate sides with lightening holes got glued together with formers and then stringers were added on the top and bottom to maintain a rounded profile.

Wing

Again the standard in parkflyer construction techniques, the wing involved interlocking the ribs into a main spar complimented by a lightweight balsa leading edge, trailing edge, and turbulators. Regardless of this, this wing, as any wing, is still best built up on a flat surface to avoid warps.

Covering

As I was looking for a scale, chrome covering scheme, I opted to cover the C-170 in chrome Solartrim . The covering itself is sticky backed and, while it will readily shrink with heat, heating up the chrome does cause it to fade and discolor slightly. As such, I opted to lay the solartrim on one small panel at a time, minimizing wrinkles and avoiding having to heat shrink the covering itself. Even though the covering is sticky-backed, I found it best to still stick down the edges with the tip of an iron.

Radio Installation

Servos get mounted in a pre-cut tray which was built in during fuselage construction. Pushrod installation is dead simple as it only required music wire to run a direct line from the servo to the control through laser-cut holes in the formers. There was no guesswork there. The receiver pretty much was just laid in the fuselage ahead of the servos. The fuselage width made this no problem at all as there was volumes of empty space. In addition, the control board for the onboard lighting system was laid in this gap as well. Battery placement is accomplished by velcro on a small balsa battery shelf just under the front windscreen. Don't worry - even my big hands were able to reach in and readily change the battery around after a flight.

My antenna of choice was a base-loaded micro antenna which is no more than about six inches long. This was routed through a gap just where the trailing edge of the wing meets the body and left to dangle in the breeze. In a faster plane, this may have presented an issue but as it stood, there were no problems with interference or range (see "Flying").

Completion

Beyond the basic construction, numerous small details were completed prior to the test flight. Things like wing struts, landing gear legs, and the cowling intakes were covered in solartrim and applied. The balsa landing gear legs were installed with small chunks of scotch tape while the wing struts used music wire on one end and small magnets (not included) on the other. The cowling intakes came as part of the kit and were laser cut from 1/32 plywood.

Once all the details were in place, a final control check was done to ensure correct direction and throw. A CG check also took place, showing that I needed to shift my 2s 420 pack to the forward half of the battery tray. This was surely due to the heavier covering adding more weight behind the CG.

Flying

The first flight took place on a sunny but cool day in March. The snow had mostly melted and the air was just above freezing, leaving our chosen flying field, a ball diamond, with mud instead of solid gravel in most areas. The large tires of the C-170 would go into use!

The question of whether or not the chrome covering would present any control issues was next on the list. With the antenna routed outside the airframe, and range check was done, varying with power on and off. Any concerns proved unfounded as the range was as good as with other, non-chrome coverings.

Finally it was time to let the C-170 take to the air.

Taking Off

One final control check was performed (a good procedure regardless of whether it's flight #1 or 101) to ensure proper direction and throttle was applied. The tail came up almost immediately and the 170 was off the ground on its own in about 25 feet at 3/4 throttle, needing only about 1/4 right rudder to maintain tracking. Further takeoffs have shown that the C-170 can be off the ground as quickly as about 10 feet at full throttle but the best scale results have been with lower throttle settings and a long ground roll.

High Speed

High speed? What high speed? That's not to say the C-170 couldn't go fast but it was just never meant to. Push the throttle ahead and the plane does indeed pick up a bit of speed with little to no trim changes but higher speed with this airframe has served no purpose. On the same note, the C-170 is capable of some aerobatics like loops and hammerheads but since they're not scale, I haven't found myself doing them much.

Low Speed

Low speed is where the C-170 excels. I found a nice cruise throttle setting around 1/2 stick (which equated to 3 oz thrust and 1.5A on the wattmeter). At this throttle, the C-170 could be flown around in nice lazy circuits, passing within mere feet of the pilot.

Landing

Is This For a Beginner?

Ideally suited to the first-time builder, the C-170 could very well suit the first time pilot with the aid of an instructor. Alternatively, the C-170 would nicely suit the self-taught pilot as their second aircraft.

Flight Video/Photo Gallery

Downloads

Conclusion

There are times when nothing beats getting out with an easy-flying plane for casual circuits. The C-170 fills this role perfectly. As an added bonus, quick construction and crisp scale lines add to the overall enjoyment.

Discussion

Reply
Thread Tools
Old May 02, 2006, 12:10 AM
WAA-08 Survivor
Griffin's Avatar
Joined May 2004
2,644 Posts
Thanks for another well done article Martin. Love that Chrome....-Steve
Griffin is online now Find More Posts by Griffin
Last edited by Griffin; May 02, 2006 at 09:18 AM.
Reply With Quote
Old May 02, 2006, 10:08 AM
Leave me alone!
Martin Hunter's Avatar
Kamloops, BC, Canada
Joined Feb 2002
15,106 Posts
Thanks, Steve. I think that chrome falls under the "labor of love" category

Martin
Martin Hunter is offline Find More Posts by Martin Hunter
Reply With Quote
Old May 06, 2006, 11:16 PM
Hold my beer and watch this!
Jeremy Z's Avatar
Northern IL
Joined Oct 2005
2,380 Posts
Boy, I like my Multiplex ARFs, but that is a beauty. I'd almost be afraid to fly it.

... then here comes you, flying the whole video 5 ft. off the deck.

That is the advantage of the cold winter days: no wind. I fly all year too. Not so many little brats polluting my soccer fields.
Jeremy Z is offline Find More Posts by Jeremy Z
Reply With Quote
Old Mar 29, 2007, 12:55 AM
Registered User
Wisconsin
Joined Nov 2003
2,954 Posts
Super Review Martin. I have to try one of these too.

Tim
ZRS4 is offline Find More Posts by ZRS4
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Article Axi-Powered Adrian Page Aviation 80 in. Electric-Designed Super Cub Laser Cut Kit Review kepople Electric Plane Talk 23 Apr 10, 2014 12:25 PM
Article Hobby Lobby Miss Stick Senior Balsa Laser Cut Kit Review wahrhaftig Electric Plane Talk 15 Apr 23, 2007 03:31 AM
Article eStar Models Air Tractor 802 Laser Cut Kit Review pda4you Scale Kit/Scratch Built 36 Feb 12, 2007 01:50 PM
Article Gunderson Aerodesign's S-1 Canard Slope Glider Laser Cut Kit Review Tram Slope 35 Jan 09, 2007 12:03 AM
Article Top Creations Bandit Aerobatic Laser Cut Kit Review wahrhaftig Electric Plane Talk 2 Sep 26, 2004 02:07 PM